Abstract

It is well documented that when a sentence focus is produced, the f0‐range of the word under focus is expanded while the f0‐range of the post‐focus words is suppressed. It is also a well‐known fact that individuals with Parkinson’s disease (PD) exhibit reduced ability in pitch modulation, resulting in a perceptual quality of ‘‘monopitch’’ in connected speech. Although the use of dopaminergic stimulation improves other physical symptoms such as balance and walking in PD, it is unclear whether a similar effect will be found on vocal folds, producing an improvement in patients’ ability in pitch modulation. In this study, five nondemented English‐speaking individuals with a clinical diagnosis of idiopathic PD (Hoehn and Yahr stage 3 and 4, off) were examined for their ability in pitch modulation in association with Apomorphine, a nonergot dopamine agonist. Two six‐word sentences with four sentence focus variations each were used. Subjects randomly produced three repetitions of each focused version at baseline and two clinical conditions: injected with placebo or apomorphine. Perception tests and acoustic analyses were conducted to determine changes in these patients’ ability to produce sentence focus. Implications of the findings are discussed in terms of speech motor control.